When using needle valve manufactured by KP-LOK the end user have the responsibility of selecting the desired packing. However, it is essential to explain what you need to consider as well as the important questions which the end user need to ask which are quite unique from those ones asked by the packing or valve manufacturer.
One thing which has been observed over the years is that an informed end user can cause many suppliers to think about their marketing strategy or change their packing technology. For instance, over the last few decades, companies such as BP, Chevron Texaco and Exxon have been a good example. The end users that have been working with these companies indicate that a great solution is achieved. Whenever valves are pulled from the supply chain or from the warehouses of end users, it implies that some low emission tags have been found.
All the international standards such as API 624, API 622, pending ISO 15848 and API 641 assume some level of valve tolerances as well as stem finishes are met such that the packing have the right standard. In addition to that, modern packing likewise has various levels of PTFE which is up to 9% and this enables compliance more readily.
There are two different issues which arise from this. The first one is about the consistency in the production of valves so that the required tolerance and design are met. For commodities which are produced in mass, this has proven to be very difficult especially with the several subcontractors.
The second one is that the mass production of the packing which passes the test above may require an increase in PTFE content so as to ease production. This practice would invalidate the tests.
So this shows an end user that the packing is not 100% graphite, so the temperature which is allowed will be reduced and the cost of maintaining the valve will increase so as to achieve a tighter tolerance of the valve. You have to pay a potential premium price which would be indicated by the supply chain. The end user likewise needs to give a structural push back on this.
Now we need to take a look at the existing valve population of the existing user so as to identify the leakers. A good FE packing is required for the route so as to replace the packing. This have been identified presently as a low emission packing but the question which you need to ask as an end user is that, will the entire packing work on an existing sit valves?
This will make the packing company quickly point to the warranty due to the fact that certain tolerance have been met for the packing to perform. Such warranty can be thrown to the bin because it does not reveal the real value to those that will use it.
So why do most users that are outside the United States use some of the tested packing in addition to others that have not been well tested through the test protocol? The answer is simply the understanding and experience because this is what is required to achieve a low emission in the field.
The industries are aware that the packing are well performed but it is kept quiet unless the end users start their investigation. However, you can count on the hand proven in situ packing which have large volume success.